The invention relates to the field of rotary compressors. In particular it encompasses a modification to such a compressor of the type particularly useful in the area of cryogenic coolers, such as the one found in U.S. Pat. No. 3,853,437 which is incorporated by reference, which, for maximum efficiency, requires a square or sinusoidal pressure wave.
The standard piston-type compressor, while providing a sinusoidal output pressure, has inherent limitations to efficiency because a rotary-to-linear motion conversion is necessary. The rotary compressor concept eliminates the necessity for such conversion. However, the porting and sealing techniques applied to rotary compressors of the prior art do not yield a true sinusoidal pressure wave. The novel modifications to the rotary compressor hereinafter described do yield the desired sinusoidal pressure output.